diff --git a/app/src/main/java/com/hippo/app/CheckBoxDialogBuilder.java b/app/src/main/java/com/hippo/app/CheckBoxDialogBuilder.kt
similarity index 100%
rename from app/src/main/java/com/hippo/app/CheckBoxDialogBuilder.java
rename to app/src/main/java/com/hippo/app/CheckBoxDialogBuilder.kt
diff --git a/app/src/main/java/com/hippo/app/EditTextDialogBuilder.java b/app/src/main/java/com/hippo/app/EditTextDialogBuilder.kt
similarity index 100%
rename from app/src/main/java/com/hippo/app/EditTextDialogBuilder.java
rename to app/src/main/java/com/hippo/app/EditTextDialogBuilder.kt
diff --git a/app/src/main/java/com/hippo/app/ListCheckBoxDialogBuilder.java b/app/src/main/java/com/hippo/app/ListCheckBoxDialogBuilder.kt
similarity index 100%
rename from app/src/main/java/com/hippo/app/ListCheckBoxDialogBuilder.java
rename to app/src/main/java/com/hippo/app/ListCheckBoxDialogBuilder.kt